Alzheimer’s can cause diabetes, study finds

Researchers believe that medicines used to treat diabetes could also be used to combat Alzheimer's disease and vice versa, after a new study showed the very close relationship between the two conditions.

The University of Aberdeen is the first study of its kind to demonstrate that Alzheimer's can cause diabetes as opposed to the other way round, as previously thought.

According to the researchers, the conditions are so closely related that drugs currently used to control glucose levels in diabetes may also alleviate the symptoms and progression of Alzheimer's disease.

The research, published in the journal Diabetologia, showed that dementia-related complications within the brain can also lead to changes in glucose handling and ultimately diabetes, which is contrary to the previous belief that diabetes begins with a malfunction in the pancreas or unhealthy diet.

The team's computer model of Alzheimer's disease found that higher levels of a gene involved in the production of toxic proteins in the brain not only led to Alzheimer's-like symptoms, but also to the development of diabetic complications.

"Many people are unaware of the relationship between diabetes and Alzheimer's disease, but the fact is that around 80% of people with Alzheimer's disease also have some form of diabetes or disturbed glucose metabolism," said study lead Professor Bettina Platt.

"This is hugely relevant as Alzheimer's is in the vast majority of cases not inherited, and lifestyle factors and comorbidities must therefore be to blame".

Further explaining the significance of the findings, she said it was always assumed that obese people get type II diabetes and then are more likely to get dementia, "we now show that actually it also works the other way around".

Also, it was previously believed that diabetes starts in the periphery, i.e. the pancreas and liver, "but here we show that dysregulation in the brain can equally lead to development of very severe diabetes - so again showing that diabetes doesn't necessarily have to start with your body getting fat - it can start with changes in the brain".

New therapeutic angle

The researchers note that the study findings provide a new therapeutic angle for Alzheimer's, and that some of the compounds used for obesity and diabetic deregulation might potentially be beneficial for Alzheimer's patients too.

"The good news is that there are a number of new drugs available right now which we are testing to see if they would reverse both Alzheimer's and diabetes symptoms," Prof Platt said.

Currently there are around 850,000 people with dementia in the UK, 62 percent of which have Alzheimer's, but this number is set to rocket to 2 million by 2051.